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authorYijing Wang <wangyijing@huawei.com>2014-06-19 16:30:30 +0800
committerBjorn Helgaas <bhelgaas@google.com>2014-07-03 16:55:07 -0600
commit31ea5d4dfe21fb50276dcd70ce268e58d57eccb4 (patch)
treee8831d2a1ea82d5b70f19044ade5f56746d92580 /drivers/pci/msi.c
parent199596ef9184ab2bc0eb43d1af9e0b723ce07840 (diff)
downloadlinux-31ea5d4dfe21fb50276dcd70ce268e58d57eccb4.tar.bz2
PCI/MSI: Cache Multiple Message Capable in struct msi_desc
The Multiple Message Capable field in the MSI Message Control register indicates how many vectors the device supports. This field is read-only, so cache it in msi_desc to avoid reading it repeatedly. Since we cache the extracted field (not the entire Message Control register), we can use msi_mask() instead of msi_capable_mask(), which is then unused, so remove it. [bhelgaas: fix whitespace, changelog] Signed-off-by: Yijing Wang <wangyijing@huawei.com> Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Diffstat (limited to 'drivers/pci/msi.c')
-rw-r--r--drivers/pci/msi.c15
1 files changed, 5 insertions, 10 deletions
diff --git a/drivers/pci/msi.c b/drivers/pci/msi.c
index 9c6995043fff..50a7e4e96da7 100644
--- a/drivers/pci/msi.c
+++ b/drivers/pci/msi.c
@@ -167,11 +167,6 @@ static inline __attribute_const__ u32 msi_mask(unsigned x)
return (1 << (1 << x)) - 1;
}
-static inline __attribute_const__ u32 msi_capable_mask(u16 control)
-{
- return msi_mask((control >> 1) & 7);
-}
-
/*
* PCI 2.3 does not specify mask bits for each MSI interrupt. Attempting to
* mask all MSI interrupts by clearing the MSI enable bit does not work
@@ -454,7 +449,8 @@ static void __pci_restore_msi_state(struct pci_dev *dev)
arch_restore_msi_irqs(dev);
pci_read_config_word(dev, dev->msi_cap + PCI_MSI_FLAGS, &control);
- msi_mask_irq(entry, msi_capable_mask(control), entry->masked);
+ msi_mask_irq(entry, msi_mask(entry->msi_attrib.multi_cap),
+ entry->masked);
control &= ~PCI_MSI_FLAGS_QSIZE;
control |= (entry->msi_attrib.multiple << 4) | PCI_MSI_FLAGS_ENABLE;
pci_write_config_word(dev, dev->msi_cap + PCI_MSI_FLAGS, control);
@@ -617,6 +613,7 @@ static int msi_capability_init(struct pci_dev *dev, int nvec)
entry->msi_attrib.maskbit = !!(control & PCI_MSI_FLAGS_MASKBIT);
entry->msi_attrib.default_irq = dev->irq; /* Save IOAPIC IRQ */
entry->msi_attrib.pos = dev->msi_cap;
+ entry->msi_attrib.multi_cap = (control & PCI_MSI_FLAGS_QMASK) >> 1;
if (control & PCI_MSI_FLAGS_64BIT)
entry->mask_pos = dev->msi_cap + PCI_MSI_MASK_64;
@@ -625,7 +622,7 @@ static int msi_capability_init(struct pci_dev *dev, int nvec)
/* All MSIs are unmasked by default, Mask them all */
if (entry->msi_attrib.maskbit)
pci_read_config_dword(dev, entry->mask_pos, &entry->masked);
- mask = msi_capable_mask(control);
+ mask = msi_mask(entry->msi_attrib.multi_cap);
msi_mask_irq(entry, mask, mask);
list_add_tail(&entry->list, &dev->msi_list);
@@ -870,7 +867,6 @@ void pci_msi_shutdown(struct pci_dev *dev)
{
struct msi_desc *desc;
u32 mask;
- u16 ctrl;
if (!pci_msi_enable || !dev || !dev->msi_enabled)
return;
@@ -883,8 +879,7 @@ void pci_msi_shutdown(struct pci_dev *dev)
dev->msi_enabled = 0;
/* Return the device with MSI unmasked as initial states */
- pci_read_config_word(dev, dev->msi_cap + PCI_MSI_FLAGS, &ctrl);
- mask = msi_capable_mask(ctrl);
+ mask = msi_mask(desc->msi_attrib.multi_cap);
/* Keep cached state to be restored */
arch_msi_mask_irq(desc, mask, ~mask);